There is nothing wrong with Portsmouth. Your first mistake is trying to race apples and oranges. Second is no system will be able to factor in the changes in the wind that occur in just one little triangle race. Your variables are wind speed, wind direction and the force of the wind as it changes the higher off the water. Thinking you can measure a boat to take all that into account is always glossed over. The ever changing wind..come up with a rating system for that...Portsmouth tries with diferent speeds, but that is just the tip of the iceberg. The other systems are no better. The more you try and make something simple, the less accurate you get....